Weld overlay



ug. 2, 1966 R. F. ARNOLDY 3,264,445

WELD OVERLAY Filed Sept. 23, 1963 4 Sheets-Sheet l /50/7700 /I Arno/dyINVENTOR.

ug- 2, R966 R. rf. AnNoLnY 3,264,445

WELD 'OVERLAY Filed Sept. 25, 1963 4 Sheets-Sheet 3 INVENTOR.

BY W f @m ug. 2, 1966I R. F'. ARNOLDY WELD OVERLAY Filed Sept. 25, 19634 Sheets-Sheet 4 @Oman f.' Arno/dy INVENTOR United States Patent O Fice3,264,445 WELD OVERLAY Roman F. Arnoldy, Houston, Tex., assigner to R.I. Patents, Inc., Houston, rTex., a corporation of rTexas Filed Sept.23, 1963, Ser. No. 311,290 Claims. (Cl. 219-76) The present inventionrelates to improvements in weld overlaying and more particularly relatesto methods of and means for weld overlaying by which improved andadvantageous results are obtained.

In my United States Patent No. 3,076,888 there is disclosed and claimedmethods of producing weld coatings or fusion welds and in my UnitedStates Patent No. 3,060,307 there is disclosed and claimed a suitableapparatus for depositing predetermined measured amounts of electrodesand metal particles by which predetermined compositions of alloy weldoverlays are obtained with very little penetration of the base metal,and hence, a minimum of dilution of the alloy overlay by the base metal.It would be highly advantageous, however, to provide a method of andapparatus for weld overlaying in which the weldable amount of the pileis considerably increased, one which permits the use of moderate forwardtravel speeds while obtaining greater increased deposition rates andallowing thorough melting and mixing of the granular materials andelectrodes to produce a uniform alloy analysis, one in which a mixingaction is provided which more thoroughly melts and mixes the ingredientsand in which the bead edges are smooth and straight and trapping of fluxor oxides is avoided between the beads when overlapping.

It would be further highly advantageous to provide such a method of andmeans for providing weld overlays on a base metal in which a completebond with a very small, easily controlled and fully predictablepenetration is obtained thereby readily providing commercial overlaps ofhigh analysis and accuracy.

The present invention is directed to such a method and means.

It is therefore an object of the present invention to provide a methodof and means for producing weld overlays in which the amount ofdeposition of metal particles is materially increased and which allows amuch higher deposition rate without impracticable and unworkable hightravel speeds.

Yet a further object of the present invention is the provision of amethod of and means for producing weld overlays in which weldableamounts of the weldable particles are very greatly increased, yet arelatively low forward travel speed is permitted to insure thoroughmelting and mixing of the granular materials and electrodes therebyproducing a uniform alloy analysis.

Still a further object of the present invention is the provision of sucha method and means which produces a stirring action to the puddle whichresults in a thorough melting and mixing of the ingredients of thepuddle.

Yet a further object of the present invention is the provision of such amethod and means by which smooth and straight bead edges are providedand in which llux or oxides are not trapped between the beads whenoverlapping.

Still a further object of the present invention is the provision of amethod of producing weld overlays in which there is substantially nopenetration of the base plate or metal by the overlay material, yetthere is complete bonding between the overlay and the base metal.

Yet a further object of the present invention is the provision of such amethod of weld overlaying in which there is substantially no penetrationof the base metal yet complete bonding of the overlay with the basemetal in 3,264,445 Patented August 2, 1966 an easily controlled andfully predictable manner so as to readily provide overlays of highanalysis Iand accuracy by commercial operations. l

It has been determined that the composition or analysis of beads weldedsometimes has composition or structure variations, or both between thesides of the bead and its center. For example, examination of a bead of18-8 stainless steel shows up to twice as much ferrite (free iron) inthe austenitic mixture may be present at the edges as in the center ofthe bead. A free swinging magnet passed close to the surface readilyidentities these areas by swinging to the bead edges. It would be highlyadvantageous to provide a method of and means for welding a bead inwhich the composition and structure of the bead is uniform. One aspectof the present invention is directed to such a method and means.

Accordingly, it is yet a further object of the present invention toprovide a method `and means by which a bead or overlay is welded to asurface in which the composition and structure of the bead is uniformand of a predetermined closely controlled composition or analysis.

Other and further objects, features and advantages of the presentinvention will be apparent from the following description ofpresently-preferred embodiments thereof, taken in conjunction with theaccompanying drawings, in which like reference numerals designate likeparts throughout the several views, and where,

FIGURE 1 is a diagrammatic View illustrating a method of weld overlayingofthe prior art,

FIGURE 2 is a schematic view, similar to FIGURE 1, illustrating a methodof weld overlaying according to the present invention and illustratingthe increase in weldable particles when overlaid to the base in a singlepass over those of FIGURE 1,

FIGURE 3 is a fragmentary, side elevational view, illustrating suitableapparatus for oscillating the electrode illustrated in FIGURE 2,

FIGURE 4 is a sectional view taken along the line 4 4 of FIGURE 3,

FIGURE 5 is a sectional view taken along the line 5 5 of FIGURE 4,

FIGURE 6 is a View similar to FIGURE 5 illustrating a modification,

FIGURE 7 is a view similar to FIGURE 3 illustrating a modification,

FIGURE 8 is a view taken along the line 8 8 of FIGURE 7,

FIGURE 9 is a fragmentary View, similar to FIGURE 7 illustrating a stillfurther modification,

FIGURE 10 is a view similar to FIGURE 9 illustrating yet a furthermodification,

FIGURE 11 is a diagrammatic view illustrating the method of obtainingsubstantially no penetration of the base metal yet at the same timeobtaining substantially complete bonding of the weld overlay,

FIGURE 12 is a side sectional view illustrating a bead or overlay weldedto a surface,

FIGURE 13 is a view taken along the line 13--13 of FIGURE 12,

FIGURE 14 is a view illustrating means for depositing weld particlesresulting in uniform composition and structural beads or overlays,

FIGURE l5 is a side view of the funnel illustrated in FIGURE 14,

FIGURE 16 is a view taken along the line 16-16 of FIGURE 15, and

FIGURE 17 illustrates the funnel of FIGURE 14 being oscillatedtransversely of its travel path.

Referring first to FIGURE l, a metal base member or plate 10 isillustrated upon which is placed particles of alloy material 12 and anarc is struck between the electrode 14 and the pile of weldableparticles 12 to melt the pile while feeding the electrode 14 at apredetermined rate thereby providing a weld overlay on the base metal 10of a predetermined composition with a minimum amount of penetration ofthe base metal 10 and hence a minimum amount of dilution of theresulting weld overlay by the metal -of the base 10. This is generallydescribed and claimed in my United States Patent No. 3,076,888 to whichreference has previously been made.

In FIGURE 1 there is no oscillation or movement in a lateral directionof the wire electrode 14. When weld overlaying without oscillation ofthe electrode 14 the maximum width of the bead is approximately 5A; inchsince this is about as far as the arc will reach =on either side of anon-oscillated electrode. Hence, the pile of weldable particles can havea maximum width of about 5A; inch in order to be completely melted bythe arc. The pile height then will be about 5/16 inch since the angle ofrepose of the granular or particular weldable material in the pile 12 isabout 45 This results in a volume of granular composition per linealinch of cubic inch. At a composition bulk density of .12 pound per cubicinch, the weight would be .0117 pound. In order to weld at a 3 to 1ratio the wire 14 used in one inch would be .0039 pound per inch.

As travel speeds of the wire electrode 14 increase above 15 inches perminute, mixing can become less complete, the surface becomes rougher andthe bead edges become irregular. Thus, using 15 inches per minute travels-peed of the wire electrode 14 to obtain a quality deposit, the ratebecomes .05 8 pound of wire per minute. This would require the use of a1/16 inch wire electrode and would result in a deposition rate of only.234 pound per minute or 14 pounds per hour at a practical travel speed.

From the foregoing, it is readily apparent that the volume and weight ofthe deposited pile 12 is generally proportional to the square of theheight or width of the pile, and that the use of a wider pile permitshigher powder to wire ratios and high deposition rates without requiringimpractical and unworkable high travel speeds of the wire electrode 14.This is accomplished by oscillating the wire electrode 14 as hereinafterset forth.

Referring now to FIGURE 2, where the reference letter a has been addedto the numerals designating corresponding parts in FIGURE 1 forconvenience of reference, the width of the pile 12a has been increasedto as much as several inches. Since the pile weight is proportional tothe square of the width of the pile 12a, the weldable amount is verygreatly increased. For example, using a pile width of 1% inch wouldrequire about one inch oscillation of the wire 14a to provide asatisfactory weld overlay on the base a. The powder weight per inch oflength now becomes 1% X5/s 1/2 1=.39 cubic inch .l2 pound per cubicinch=.0468 pound per inch. Wire deposition at a 3 to l ratio becomes.0156 pound per inch at 15 inch per minute travel speed of the wireelectrode 14a or a deposition of 4 times as much material by making thepile width twice as much as that of the pile 12 in FIGURE 1 and thusallows use of a i732 inch wire. Further, the use of still larger pileswill allow use of electrode wires of very large sizes with depositionrates proportionately higher, as for example a 1A inch wire allows adeposition rate of 3.75 pounds per minute or 225 pounds per hour with2.5 inches wide oscillation.

Advantageously, the oscillation of the wire electrode 14a, when combinedwith arcing to the top of the pile 12a, permits the use of relativelylow forward travel speeds of the electrode 14a which results in morethorough melting and mixing of the granular alloy materials of the pile12a and electrode wire 14a producing a uniform alloy analyses, since theweld puddle is fluid for a considerably longer period of time than inthe method exemplified by FIGURE 1, without any substantialcontamination by the base metal.

In addition, the travel of the electrode 14a over the puddle formed bythe electrode 14a and the pile 12a of granular alloy materials producesa stirring action which more thoroughly melts and mixes the components.Since a low forward speed of the electrode 14a is utilized, the beadedges become smooth and straight and prevent trapping of uid or oxidesbetween beads when overlapping.

Preferably, the wire electrode 14a should be oscillated in pendulumfashion, so that the end of the electrode 14a rises at each end of itstravel at the sides of the pile 12a which prevents short circuitingagainst a previous bead welded to the base on one side and on the freeside gives a momentary high voltage which smooths out the edge or beadat that side.

Referring now to FIGURE 3, an apparatus according to the invention isillustrated for obtaining the pendulum like oscillation of theelectrode, -to which the reference letter b has been added to partscorresponding to those of FIGURE 2. In this embodiment a generallytubular body 16 is provided to which is threadedly or otherwise securedthe nozzle 18 through which the wire electrode 14b extends. In thisembodiment variable linear oscillation of the wire electrode 14b isobtained by utilizing the crank 20 consisting of the crank arm 22pivotably secured by the pivot 24 to the body 16 and the crank arm 24 issecured to the rod 26 which extends through the guide 28 and isconnected to the follower 30 which slides in the milled heart-shapedslot 32 of the constant displacement cam 34. Thus, rotation of the cam34, by any suitable means not shown, causes reciprocation of the rod 26which, through the crank 20, causes a pendulum-like oscillation of thebody 16 and hence, the wire electrode 1419i.

In the arrangement illustrated in FIGURE 3 there is provided means forvarying the linear oscillation of the electrode 14h. This isaccomplished by having the arm 22 and the rod 26 pivotally connected bymeans of the pivots 36 and 38, respectively, to the arm 24 and, providedwithin the hollow arm 24 is a pivot 40, which is fixed by means notshown, secured to the movable member 42, the position of which isadjusted by -the adjusting screw 44. Thus, adjustment of the adjustingscrew 44 causes a movement of the arm 24 which, in turn, varies thewidth of the oscillation of the electrode 14b.

If desired, of course, the linear oscillation of the wire electrode 14bmay be varied by any suitable means. For example, with reference toFIGURE 6, the reference letter c has been added to parts correspondingto those of FIG- URE 3, a fixed crank 20c is -provided and an additionalarm 21 is connected to the body 16e rather lthan the crank arm 22 asillustrated in FIGURE 3. If it is desired to change the width of theoscillation of the wire electrodes 14C in this embodiment, diiTerentsize cams, such as illustrated in FIGURE 3, are utilized.

In some instances it may be desirable to change the direction ofoscillation of the wire electrode 14b. Such an arrangement isillustra-ted in FIGURE 5 to which reference is now made and in which thereference letter d has been added to parts corresponding to those ofFIG- URES 3 and 6. In this embodiment, the arm 21d is directly connectedto the cam arm 26d without any crank arrangement so that oscillation ofthe body 16d and hence the wire electrode 14d is in the directionillustrated which is generally at right angles to the direction ofoscillation of the wire electrode 14C in FIGURE 6 and 14h in FIGURE 3.

No further description is given of the means for oscillatingthe body,.and hence the wire electrode, in these views as a wide variety ofarrangements may be utilized as desired and to accommodate theconditions of use.

Referring now to the details of construction of the apparatus of FIGURES3 and 4, and with particular reference to FIGURE 4, the upper end of thebody 16 is enlarged, as at 48, and is provided with the' front and.

back pivot members 50 and 52. A fixed body member 54, provided with theflat slide surfaces 56 and 58, which engage the inner flat slidesurfaces 60 and 62, respectively, of the pivot members 50 and 52, issecured by means of the shoulders 64 to the body 66 and by the set screw68.

Disposed in the fixed member 54 is the passage 70 which communicateswith the passage 72 in the body 16 and in the enlarged body portion 48and with the passage 74 in the nozzle 18 through which the wireelectrode 14b slidably extends. The inwardly projecting portion 76 inthe inner portion of the enlarged portion 48 of the body 16 terminatesat .the axis of they pivot so that there is essentially no motion at thepoint the Wire enters the passage 76 and has a generally tapered opening78 so that as the enlarged body portion 48 and the body 16y areoscillated the wire electrode V14b can be threaded into the passage 76.

There are provided a pair of pivot pins 80 and 82 which pivotally secureAthe large body portion 48 to the stationary body member 54 so that onlythe large body portion 48, the body 16 and the nozzle 18 are `oscillatedand the remainder of the body parts remain fixed with the body 66 of thefeeder.

As illustrated, a tube 84 is provided through which the granular alloyweld materials making up the pile 12b are deposited in advance of thetravel of the nozzle 18 and, for submerged welding, a tube 86 isprovided to deposit flux 13 on -top of the pile 12b of particulate weldmaterial. If desired, and as illustrated, the tubes 84 and 86 may besecured to the body 66 and remain stationary, the openings in thesetubes being sufficiently large -to provide the desired width of pile 12band flux 13 for the oscillation of the wire electrode 14b so that onlythe electrode 14b oscillates. The remainder of the welding assembly maybe the same as illustrated in my U.S. Patent No. 3,060,307 so thatmeasured amounts of wire electrode 14b and amounts of granular materialmaking up the pile 12b and flux 13 are deposited on the work or basemetal b which is to be provided with an overlay bonded to its surface.Accordingly, no further details of the feeder arrangement is given ordeemed necessary.

Preferably, the electrode 14b, .and hence the body 16 and the nozzle 18should be directed at about a 20 angle in a trailing direction to thesurface of the work 1411.

If desired, either or both the tubes for the metal pile and flux may befixed and the entire body of themetering or feeder head for `the wireelectrode, granular metal pile and flux oscillated. Su-ch an embodimentis illustrated in FIGURES 7 and 8, to which reference is now made, and-to which the reference letter e has been added to numerals designatingparts corresponding to those of FIG- URES 3 yand 4. In this embodimentthe body 66e is secured to a pivot shaft 22e which is oscillated by ameans of a constant displacement cam, not shown, such as illustrated inFIGURE 3. The pivot shaft 22e is journalled by means of theanti-friction assembly 88 within the boom 90 by which the travel of themetering head is accomplished and which supports the various parts inrelation to the work 10e.

Connected to the boom 90 by means of the bracket 92 is the funnel 94which isv maintained in a stationary position and which receives fromthe tube 84e the particulate metal alloying materials for deposit on thework 10e as the pile 12e. The funnel 94 is of sucient size to receivethe alloying particles from the body 66e through the tube 84e during itsoscillation as best illustrated in FIGURE 8.

A similar arrangement is provided for the ux tube 86e, but because ofspace limitations, only the funnel 86e is illustrated.

The arrangement of the electrode and tubes for providing particulate orgranular weldable material may be varied considerably as desired and .toaccommodate conditions encountered in use. Such modified arrangementsare illustrated in FIGURES 9 and l0, to which the reference letters fand g, respectively, have been added 4to numerals designatingcorresponding parts in the preceding figures.

Referring iirst to FIGURE 9, an arrangement is illustrated in that .theflux tube 861 is disposed behind the electrode 14]c but the ux tube 86fis arranged so that the ilux flows across the wire electrode 18)i as itis oscillated transversely of the direction of travel.

In FIGURE 10, the flux tube 86g is arranged concentric with land aboutthe nozzle 18g so that the flux 13g flows `onto the pile 12g ofparticles of weldable material and is oscillated with the wire electrode14g.

.No further parts are illustrated in FIGURES 9 and l0 as the remainingparts are the same and operate in lthe same manner as in preceding viewsland no further descri-ption is deemed necessary or given.

As previously mentioned, in producing Weld overlays on steel or othermetal plates, there has been some difiiculty in controlling the amountof penetration and it has been dicult to obtain the values desired, thatis, provide complete bonding with minimum penetration. As an example ofone set of welding conditions, utilizing the process set forth in myUnited States Patent No. 3,076,888, no penetration of the base -plate isobtained, however, close control of current, base preheat, travel speedand other factors are necessary to insure complete bonding withoutpenetration as an incremental increase in current causes penetration tooccur, land the range of current setting between 1/64t inch penetrationand l/ inch penetration is small. It would be highly desirable toproduce a bond with a very small and easily controlled and fullypredictable penetration. In this embodiment of 4the invention thesurface of the work or metal base is prepared by suitable means so as tohave an exposed surface `area of 11/2 to 4 times the normal flat orprojected area of the surface. By a normal at surface is meant one thathas a surface of R.M.S. or less, average.

Referring now to FIGURE 1l, in which the reference letter h has beenadded to reference numerals designating corresponding parts throughoutthe preceding views, a series of thread like serrations are provided,such as by machining, in the plate or work piece 10h. These may berolled, the `surface may be blasted with rough material, such as flintand the like so that the exposed surface is 11/2 to 4 times more thanthat of a generally flat surface. In the serrations 15 illustrated inFIGURE l1, Ia distance of between 1&4 to '0732 of an inch between crestsof the thread, and a distance of from 1//64 inch to 1/16 inch betweenthe crest and the root are satisfactory to provide an exposed surfacearea of 11/2 to 4 times the normal flat or projected area.

When utilizing the increased exposed surface area within the range setforth, the temperature of the weld overlay is sufficient to melt .thenarrow projections of the surface and cause bonding thereof to the workin a uniform manner whereas the same temperature of the molten overlaymaterial would not be sufciently high to produce penetration and uniformbonding of the plate if the surface were not so prepared.

The preparation of the exposed surface of the base or work isparticularly advantageous when combined with oscillating the electrodeand forming an -arc between the electrode and the top of the pile, allas previously described.

This is particularly advantageous in producing overlays of high analysisaccuracy, for example an overlay of AISI type 304L stainless steel. Thismaterial has a carbon content of .04 maximum for an overlay. The usualbase metal will have .25 to .40% carbon.

Percent Carbon from overlay 2/3 .02:.0133 Carbon from base metal 1A.36=.l2

Total .1333

This amount is over three times that allowed to make 304L stainlesssteel.

Similarly, the dilution effect will cause the amounts of other elementsto fall out of the allowable range. Thus, by controlling the penetrationwhich is readily and easily accomplished, overlays of high analysisvaccuracy within allowable amounts are readily obtained.

As previously mentioned, the composition or structure or both of thebead or overlay varies between its center and edges. Referring now toFIGURES 12 and 13, in which the reference letter i has been added toreference numerals designating parts corresponding to those of thepreceding views, the overlay or bead 11i of 18-8 stainless steel isshown welded to the work or base 10i. The sides x of the overlay or bead11i have about twice as much ferrite (free iron) as the center y asdetermined by the test previously mentioned.

To overcome this disadvantage and to prevent this condition fromhappening, and with reference to FIG- URES 14, l and 16, in which thereference letter j is added to reference numerals designatingcorresponding parts of the previous gures, there is provided a funnel84j which deposits weld particles 12j on the work or base j in such amanner so that there are more weld or alloy particles at the edges thanin the center thus requiring less flow of weld or yalloy material to theedges from the center to complete the mixture. To this end, aplow-shaped or generally triangularly-shaped member- 85]' is provided atthe trailing end of the funnel 84j which extends transversely of thepath of movement of the funnel 84j. As best seen in FIGURE 14, thiscauses the metal pile 12j to be deposited on the work 10j in the form oftwo triangular metal piles 13j and 15j which intersect one another.Preferably, the angle z of the sides of the projection or plow 85]', isabout twice the angle of repose of the granular metal pile or weldparticles 12j. In most cases, this is about 45. Any desired shapedmember, however, may be used which deposits enough metal on the sides toavoid nonuniform composition or structure of the bead or overlay.

In order to allow for the spreading 'action of the projection or plow85j, the funnel or tube 84j may be elongated to have a length greaterthan its width, for example, a length twice its width, as best seen inFIGURES 15 and 16.

In some cases it may be desirable to oscillate the funnel or tube. Suchan arnangement is illustrated in FIGURE 17, to which reference is nowmade and in which the reference letter k has been added to referencenumerals designating parts corresponding to those of the precedingfigures. It is noted that the sides 13k and 15k of the pile 12k havemore weld particles than its center portion. In this embodiment, thefunnel or tube 85k is connected to the portion of the assembly whichoscillates, such :as the body member 66. The opening in the funnel ortube 84k should be sufficiently elon gated or narrowed in its directionof travel to prevent throwing weld particles out of the effectiveoscillatory path of the electrode.

Similarly, in oscillating the tube or funnel for depositing weldparticles or flux in the embodiments illustrated by the precedingiigures, the opening is elongated and narrowed in lthe direction oftravel. For example, in FIGURES 7 and 8, the bracket 92 and funnel 94would be eliminated and the tube 84e extend to the pile 12e, :as inFIGURE 4, and the opening of the tube 84e elongated and narrowed, yaspreviously described.

It is desirable in these various embodiments of the invention to bringthe weld particles into the weld zone at a point which is of lessdistance from the arc than the length of the molten puddle and oneaspect of the invention is directed thereto. This is particularlyadvantageous where there are changes or fluctuations in travel speed orrate of wire feed while the electrode is traveling from one point overthe distance to the point of introduction of the pile of weldableoverlay particles on the work or base will vary within the distancebetween the electrode and the point of weldable particle deposition. Ifthis distance is greater than the molten puddle length, the analysis canvary outside the specified range. If this distance is shorter than thepuddle length, the smaller .and greater amounts of weldable overlayparticles are integrated into the same puddle and cancel out thevariation.

Combining this aspect lof the invention with the other aspects thereofinsures uniform composition of predetermined analysis land structure ofthe overlay with relatively fast rates of deposition land greaterthickness of the -overlay and a minimum of dilution of the overlay withthe base metal, but with good bonding.

The present invention, therefore, is well suited and adapted to attainthe objects land ends yand has the advantages and features mentioned aswell as others inherent therein.

Numerous changes may be made inthe details, arrangement of parts, andsteps of the invention which is to be limited only by the spirit thereofas dened by the scope of the appended claims.

What is claimed is:

1. A method `of producing a weld overlay on the surface of a basecomprising,

placing on the surface of the base a pile of electrically conductive,weldable overlay particles in a predetermined amount, the width of thepile being in excess of that which can be completely melted by alinearly moving electrode without substantial penetration of the base,

creating an arc from an electrode to the upper porti-on of the pile, and

oscillating the elect-rode transversely of the pile while melting andmoving the electrode along the length of the pile at a speedcorresponding to the linearly moving electrode thereby melting the pileand a thin skin of the base and bonding the overlay of predeterminedcomposition to the base without substantial dilution of the overlay bythe material of the base. 2. The method of claim 1 where, the surfacehas an exposed area of about 11/2 to about 4 times that of asubstantially flat surface. 3. A method of producing a weld overlay onthe surface of a base comprising,

placing on the surface of theV base a pile of electrically conductive,weldable overlay particles in a predetermined amount, the width of thepile being in excess of that which can -be completely melted by alinearly moving electrode without substantial penetration of the base,the height of the pile being substantially the height of the material asdetermined by the angle of repose of the particles,

creating an arc from an electrode to the upper portion of the pile, andoscillating the electrode transversely of the pile while melting andmoving the electrode along the length of the pile at a speedcorresponding to the linearly moving electrode thereby melting the pileand a thin skin of the base and bonding the loverlay yof predeterminedcomposition to the base without substantial dilution of the overlay bythe material of the base. 4. The method of claim 3 where, the surfacehas an exposed area of about 11/2 to about 4 times that of asubstantially flat surface. 5. A method of producing a weld overlay onthe surface of a base comprising,

depositing on the surface of the base a pile of electrically conductive,weldable overlay particles in a predetermined amount, the width of thepile being in excess of that which can be completely melted by alinearly moving electrode without substantial penetration of the base,

depositing flux over the pile,

creating an arc from an electrode t-o the upper portion of the pile, and

oscillating the electrode transversely Iof the pile while melting andmoving the electrode along the length of the pile at a speedcorresponding to the linearly moving electrode thereby melting the pileand a thin `skin of the base and thereby bonding the overlay ofpredetermined composition to the base Without substantial dilution ofthe overlay by the material of the base.

`6. The method of claim where the surface has an exposed area from about11/2 to about 4 times that of a substantially flat surface.

7. A method of producing a weld overlay on the surface of a basecomprising,

depositing on the surface of the base a pile of electrically conductive,weldable overlay particles ,in a predetermined amount,

the width of the pile being in excess ,of that which can be completelymelted by a linearly moving electrode without substantial penetration ofthe base,

the height of the pile being determined by the angle of repose of theweldable overlay particles,

depositing a flux over the pile,

creating an arc from an electrode to the upper portion Iof the pile, and

oscillating the electrode transversely of the pile and while melting andmoving the electrode along the length lof the pile at a speedcorresponding to the linearly moving electrode thereby melting the pileand a thin skin of the base and thereby bonding the overlay ofpredetermined composition to the base Without substantial dilution ofthe overlay by the material of the base.

8. The method of claim 7 Where the surface has an exposed area fromabout 11/2 to about 4 times that of a substantially at surface.

9. A method of producing a Weld overlay on the surface of a basecomprising,

depositing on the surface of the base a pile lof electricallyconductive, weldable overlay particles in a predetermined amount, thesides -of the pile containing more of said particles than the center,

the Width of the pile being in excess of that which can be completelymelted by a linearly -moving electrode without substantial penetrationof the base,

creating an arc from an electrode to the upper portion of the pile, and

oscillating the electr-ode transversely of the pile at a speedcorresponding to the linearly moving electrode while melting and movingthe electrode along the length of the pile thereby -melting the centerand side of the pile and a thin skin of the base and bonding the overlayIof predetermined substantially uniform compositi-on and structurewithout substantial dilution of the overlay with the material of thebase. 10. The method of claim 9 in Which the sides of the pile, whenviewed transversely, are generally in the form of triangles and thecenter of the pile is formed by the intersection of the inner sides ofthe triangles.

11. The method of claim 10 Where the sides of the triangles aregenerally at the angle of 4repose of the overlay particles. i

12. A -method 'of producing a weld overlay on the surlface of a basecomprising,

depositing 4on the surface of t-he base a pile ofelectrically-conductive, weldable overlay particles, and

creating an arc from an electrode to the upper portion of the pilethereby providing a molten puddle, the point of depositing the weldableoverlay particles being less distance from the arc than the length ofthe molten puddle.

13. A method of producing a Weld overlay on the surface of a basecomprising,

depositing on the surface of the base a pile of electrically-conductive,weldable overlay particles, creating an arc from an electrode to theuppe-r portion of the pile thereby providing a molten puddle,

the point of depositing the weldable overlay particles being lessdistance `from the arc than the length `0f the molten puddle, the Widthof the pile being in excess of that which can be completely melted by alinearly moving electrode without substantial penetration of the base,and

oscillating the electrode transversely of the pile while melting andmoving the electrode along the length of the pile at a speedcorresponding to the linearly moving electrode.

14. The method of claim 13 where the :sides of the pile contain moreweldable overlay particles than the center thereof.

15. The method yof claim 14 where the surface has an exposed area fromabout 11/2 to about 4 times that of a substantially flat surface.

References Cited by the Examiner UNITED STATES PATENTS 2,841,687 7/1958Richter 219-76 2,931,886 4/1960 Nunnelee et al. 219-76 3,019,327 1/1962Engel 219-76 3,076,888 2/1963 Arnoldy 219-73 3,118,047 1/1964 Johnson219-76 3,139,510 6/1964 Marion 219-76 RICHARD M. WOOD, Primary Examiner.JOSEPH V. TRUHE, Examiner.

1. A METHOD OF PRODUCING A WELD OVERLAY ON THE SURFACE OF A BASECOMPRISING, PLACING ON THE SURFACE OF THE BASE A PILE OF ELECTRICALLYCONDUCTIVE, WELDABLE OVERLAY PARTICLES IN A PREDETERMINED AMOUNT, THEWIDTH OF THE PILE BEING IN EXCESS OF THAT WHICH CAN BE COMPLETELY MELTEDBY A LINEARLY MOVING ELECTRODE WITHOUT SUBSTANTIAL PENETRATION OF THEBASE, CREATING AN ARC FROM AN ELECTRODE TO THE UPPER PORTION OF THEPILE, AND